Faced with a shortage of eligible inmates, the state's "boot camp" prison has changed its requirements to accept older and more dangerous inmates serving longer sentences.

Under changes that went into effect Oct. 1, medium-security inmates will be eligible for boot camp for the first time.

The boot camp is styled after a military training camp. It features rigorous discipline, hard physical labor and self-awareness programs. The camp is supposed to give inmates motivation to resist committing crimes when they return to their neighborhoods.

The maximum sentence for eligible inmates will also be increased from five years to eight years. Inmates as old as 32 are now being considered for the program. The age limit had been 26. In addition, inmates serving time for burglary will be eligible for the first time.

The changes appear to conflict with one of the stated goals of boot camp when it began a year ago -- to turn the youngest and least violent offenders away from crime through the rigorous six-month program.

Gregory M. Shipley, a spokesman for the prison system, said the changes "conflict to an extent" with the program's goals. "But you still have to look at the fact that [the inmates] are still serving their first sentence in the Division of Correction. They may be older, but hopefully we can still change their mind."

The rules still say that only inmates serving their first sentence in a state prison can go to boot camp. Inmates convicted of crimes of violence or drug offenses are still ineligible.

A large chunk of the inmate population is still not eligible for the boot camp, because they are too old, their sentences are too long or their crimes are too serious.

The boot camp in Jessup opened in August 1990. So far, 327 inmates have made it through the six-month program, which emphasizes discipline, physical training and work. The inmates, in their distinctive blue uniforms, can be seen most days cleaning roadways or polishing brass in the State House.

Prison officials have fixed on boot camp as a prime way of easing overcrowding in the system, which now holds more than 18,500 prisoners. Most inmates who make it through the six-month program have the rest of their sentences wiped out.

Under the new rules, inmates who are serving sentences of more than five years will have to serve 25 percent of their terms, which means they would end up serving time in prison in addition to their six months in boot camp.

"We certainly believe the boot camp program is a valuable program," Shipley said. "If we can reach more inmates with this program, we want to do that, without increasing the risk level of the inmates we put in there."

Shipley said the state has never filled all the beds at the boot camp with actual boot camp prisoners. This week, he said, about 60 inmates who were not in the boot camp program were being housed on the boot camp grounds.

He said corrections officials hope the new eligibility rules will produce a larger pool for the boot camp.